KR20150041291A - Card-Shaped Secondary Battery Cell - Google Patents

Abstract

The present invention provides a secondary battery cell wherein an electrode assembly having a stack structure in which a plurality of sheet-type electrodes and a plurality of separation membranes are alternately stacked, is mounted in a card-shaped battery case in a sealed state; and at least one of an uppermost electrode and a lowermost electrode of the electrode assembly has one surface which is facing a separation membrane and is coated with an electrode active material and the other surface which is not coated with an electrode active material.

Description

A card-shaped secondary battery cell {Card-Shaped Secondary Battery}

The present invention relates to a card-shaped secondary battery cell.

The smart card is a plastic product using a magnetic card, whereas the smart card includes an integrated circuit, so that a large capacity memory, bidirectional communication, and information protection functions can be performed. Since the capacity is much higher, it is possible to perform various additional functions requiring additional information storage, and thus it is widely used in financial, commerce, transportation, identification and security fields.

On the other hand, demand for portable electronic devices that can be carried by modern people is increasing, and demand for portable batteries capable of charging small electronic devices is also rapidly increasing. Particularly, the use of electronic devices (for example, mobile devices, digital cameras) that require a large amount of power is increasing, and the variety and variety of portable electronic devices are increasing the kinds and number of devices carried by consumers. The demand for high capacity portable batteries is increasing day by day.

Such a portable battery needs to be minimized in its volume and weight for the convenience of the consumer. However, the conventional portable small-sized battery has a very small internal size, has a limitation in realizing a high-capacity battery, and has a problem that the battery is very poor in durability that must be provided.

Therefore, the key to the practical use of the portable battery is its size and safety, and there is a growing demand for developing a technology capable of increasing current capacity and safety while maintaining an appropriate level of ease of carrying.

In addition, there is an increasing demand for a product capable of simultaneously performing functions of a smart card and a charging function of a portable electronic device so as to utilize the portable space of a consumer as much as possible.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems of the prior art and the technical problems required from the past.

It is an object of the present invention to assemble an electrode assembly by performing only a lamination process of a plurality of electrodes and separation membranes interposed between the electrodes similar to a bi-cell structure of a multilayer structure, To provide a battery cell which is easy to manufacture as an assembly and is compact overall and excellent in structural stability.

It is still another object of the present invention to provide a secondary battery cell including a smart card function and a charging function of a portable electronic device.

It is still another object of the present invention to provide a method of manufacturing a semiconductor device in which the current collector of the uppermost electrode is formed to be relatively thicker than the current collector of the electrode located in the inner side so that overheat or explosion due to an internal short circuit due to contact between the negative electrode active material and the cathode active material by the needle- Which can prevent the battery cell from being damaged.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a rechargeable battery cell comprising a stacked electrode assembly in which a plurality of sheet-like electrodes and separators are stacked alternately, At least one of the uppermost layer electrode and the lowermost layer electrode of the assembly may have a structure in which an electrode active material is coated on one side facing the separation membrane and an electrode active material is not coated on the other side.

That is, even though the electrode active material is applied to one surface of the current collectors of the uppermost electrode and the lowermost electrode, which correspond to the outermost surface of the electrode assembly, the secondary battery cell of the present invention does not affect the charge / discharge capacity, The electrode active material may not be coated on the other surface of at least one of the uppermost layer electrode and the lowermost layer electrode.

Generally, when needle-shaped conductors pass through a battery, the main cause of the explosion or ignition of the battery is due to high resistance heat caused by electric current passing through the contact resistance portion between the cathode active material and the anode active material due to the deformation of the electrode when the conductor passes through.

Therefore, since the electrode assembly according to the present invention includes a structure in which the electrode active material is not coated on the other surface of at least one of the uppermost electrode and the lowermost electrode, it is possible to prevent direct contact between the needle- Bar, and internal short-circuit due to their direct contact.

In addition, the conventional stack / folding type electrode assembly has a structure in which a plurality of unit cells (full-cell or bi-cell) are mounted on a separator sheet which is formed integrally in one direction and then folded folding process, the electrode assembly of the present invention is formed by stacking a plurality of electrodes and separation membranes interposed between the electrodes, similar to a bi-cell structure of a multi-layer structure, To assemble the electrode assembly. As a result, it is possible to manufacture a compact battery cell and to omit the folding step in the manufacturing process, thereby shortening the manufacturing time and reducing the defective ratio to a large extent .

In one specific example, each of the uppermost electrode and the lowermost electrode of the electrode assembly may be coated with an electrode active material on one side facing the separation membrane and no electrode active material on the other side.

Specifically, an electrode assembly according to the present invention comprises:

A first electrode comprising at least one double-coated electrode sheet (1a) coated with a first electrode active material on both sides and at least two single-coated electrode sheets (1b) coated with a first electrode active material on one surface;

A second electrode composed of two or more double-coated electrode sheets 2a on both sides of which a second electrode active material is applied; And

Four or more separation membranes interposed between the electrode sheets;

. ≪ / RTI >

In one specific example, the two or more single-sided coated electrode sheets 1b may be positioned at the outermost ends of the electrode assembly such that the uncoated side faces the outer surface of the electrode assembly, for example, And the second electrode may be a cathode.

On the other hand, the current collector of the first electrode may be 5 to 30% thicker than the current collector of the second electrode. Specifically, among the first electrodes, the current collector of the one- Of the collector sheet 2a of the double-coated electrode sheet 2a.

Therefore, the one-sided coated electrode sheet 1b is located at the outermost electrode layer of the electrode assembly. By applying a current collector thicker than the second electrode and the double-sided coated electrode sheet 1a located inside, the outer needle- And has an effect of preventing an internal short circuit when the battery is penetrated.

If the current collector of the single-sided coating electrode sheet 1b is thicker than the current collector of the double-sided coating electrode sheet 2a of the second electrode by less than 5%, it is difficult to exert the effect of preventing the internal short circuit. Conversely, , The thickness and weight of the battery significantly increase, which is not preferable.

In one specific example, the electrode assembly may include a gel polymer electrolyte.

The gel polymer electrolyte is capable of reducing the contact area of the electrolyte in contact with the electrode in comparison with the electrolyte in the form of a solution, thereby inhibiting adverse reaction between the electrode and the electrolyte, Thereby reducing the internal vapor pressure

Specifically, the electrolyte is a gel polymer electrolyte containing a monomer and an electrolyte for forming a crosslinked polymer. More specifically, the gel polymer electrolyte includes a polymerization initiator, a plasticizer, and a lithium salt .

The present invention provides a method for manufacturing a battery cell comprising the gel polymer electrolyte,

Mounting the electrode assembly on a battery case;

Injecting a mixed solution containing a crosslinking polymerizable monomer, a polymerization initiator, an electrolyte solution and a lithium salt into the battery case and sealing the same;

Polymerizing the cross-linking polymerizable monomer;

A formation step of activating the cell; And

An aging step of stabilizing the activated cell;

And a method of manufacturing the secondary battery cell.

In one specific example, the degassing step may be omitted in the conversion step of activating the battery.

Generally, during the manufacturing process of the battery, the first charging is performed in the chemical conversion step, and the gas is generated due to the chemical reaction inside the battery. However, as described above, the battery cell including the gel polymer electrolyte according to the present invention generates a relatively small amount of gas as compared with the amount of generated gas of the general cell. Therefore, additional degassing process is performed in the process of manufacturing the secondary cell There is an effect that the safety of the product is not hindered.

Also, in the secondary battery cell according to the present invention, even when a liquid electrolyte is used, a relatively small amount of electrolyte can be used, so that the amount of reaction with the active material can be remarkably reduced, and an additional degassing process can be performed .

In one specific example, the electrode assembly may be sealed in a pouch-shaped case of a laminate sheet comprising a metal can or metal layer and a resin layer.

For example, the pouch-type case may be formed as a plate-like shape having a generally rectangular parallelepiped structure having a small width and a small overall thickness. Wherein the pouch-shaped case comprises an outer covering layer made of a polymer resin having excellent durability; A barrier layer made of a metal material exhibiting barrier properties against moisture, air, and the like; And an inner sealant layer composed of a polymer resin that can be thermally fused, are laminated in this order.

In another specific example, the pouch-type case may have a variety of structures. In the case where the electrode assembly is housed in the housing portion formed on the upper and / or lower inner surface of the unit, the upper and lower contact portions Or may be sealed by adhering.

A protection circuit module (PCM) may be electrically connected to an electrode terminal of the secondary battery cell. A USB port of a universal serial bus standard may be connected to an external input / output terminal of the PCM. have.

In one specific example, the card-shaped battery case may include configurations for a smart card function. For example, the battery case may include a radio-frequency identification ) Function and an integrated circuit (IC) chip.

The card-shaped battery case may have a structure in which a thin film is further coated on the outer surface of the pouch-shaped case.

The film may be a film comprising a polymer material such as PET (polyethylene terephthalate), PBT (polybutyl terephthalate), PEG (polyethylene glycol) or the like constituting the front and back surfaces of the battery. However, it is not limited to these materials, and it is possible to arbitrarily select and use them according to properties required from conventionally known resin materials.

In one specific example, a barcode may be printed on the outer surface of the battery case, or a barcode label may be attached thereto. For example, the barcode label may include a base film made of a resin having transparency and printability, The base film may be made of polyester (PE) or polyethylene terephthalate (PET).

In this case, the polyester has a high transparency, is very strong against moisture and temperature, and is not easily torn. The polyethylene terephthalate (PET) is easy to apply to electronic products requiring durability, heat resistance and abrasion resistance Do.

As described above, in the card-shaped secondary battery cell according to the present invention, at least one of the uppermost electrode and the lowermost electrode is a novel battery cell in which an electrode active material is coated on one side facing the separation membrane, and an electrode active material is not coated on the other side Structure, so that the size of the internal configuration can be effectively reduced, and a relatively large amount of power can be supplied to the external device.

In addition, since the external device includes the charging function and the function of the smart card, there is an advantage that the portable space of the consumer can be utilized effectively.

Since the current collector of the uppermost electrode is formed to be relatively thicker than the current collector of the electrode positioned on the inner side, it is possible to fundamentally prevent overheating or explosion due to an internal short circuit due to contact between the negative electrode active material and the positive electrode active material There is an effect.

1 is a schematic plan view showing configurations of an electrode assembly before assembly according to one embodiment of the present invention;
2 is an enlarged partial enlarged view of a portion of an electrode assembly according to one embodiment of the present invention;
3 is a schematic perspective view of an electrode assembly and a pouch-shaped case according to one embodiment of the present invention;
4 is a schematic perspective view of a pouch-shaped battery cell having an electrode assembly according to an embodiment of the present invention;
5 is a schematic perspective view showing the internal structure of a pouch-shaped battery cell of FIG. 4 and a secondary battery including the configurations for a smart card function;
6 is a schematic plan view of a card-shaped secondary battery cell according to one embodiment of the present invention;
FIG. 7 is a schematic diagram for supplying power to an external device using the card-shaped secondary battery cell of FIG. 6;

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited by the scope of the present invention.

FIG. 1 is a schematic plan view showing configurations of an electrode assembly before assembly according to one embodiment of the present invention.

Referring to FIG. 1, a stacked electrode assembly 130 in which a plurality of sheet-like electrodes 121, 161, 122, 162, 123 and separators 150, 151, 152, Electrode active materials are coated on one surface 175 and 177 of the uppermost electrode 123 and the lowermost electrode 121 of the electrode assembly 130 facing the separators 150 and 153 and the other surfaces 170 and 172 are coated with an electrode active material, The electrode active material is not coated.

Specifically, the first electrode 120 of the electrode assembly 130 includes a double-sided coating electrode sheet 122 on which the first electrode active material is applied on both surfaces, and a first electrode active material coated on one surface 175, Coated electrode sheets 121 and 123 and the second electrode 160 is composed of two double-coated electrode sheets 161 and 162 having the second electrode active material coated on both surfaces thereof. Four separators 150, 151, 152 and 153 are interposed between the first electrode 120 and the second electrode 160, respectively.

The single-sided coating electrode sheets 121 and 123 are positioned at both outermost ends of the electrode assembly 130 such that the non-coated surfaces 170 and 172 face the outer surface of the electrode assembly.

2 is an enlarged partial enlarged view of a portion of an electrode assembly according to one embodiment of the present invention.

Referring to FIG. 2, the first electrode 120 is an anode, the second electrode 160 is a cathode, and the current collector 110 of the one-side coated electrode sheet 121 of the first electrode 120 Is formed to be 15% thicker than the current collector 167 of the double-side coated electrode sheet 161 of the second electrode 160.

2, the needle-shaped conductor 700 is first brought into contact with the current collector 110 of the one-side coated electrode sheet 121 located at the outermost periphery The current collector 110 is bent downward and the cathode active material 125 coated on the inner surface of the current collector 110 is also bent as the needle-like conductor 700 flows. This phenomenon occurs when the current collector 110 made of a material having a ductility (for example, aluminum) is bent in the direction of penetration by the downward force of the needle-like conductor 700, and the frictional force with the needle-shaped conductor 700 is increased , So that the cathode active material 125 coated on the inner surface of the cathode current collector 110 is dried inward. Therefore, even when the needle-shaped conductor 700 reaches the negative electrode active material 165 of the separator 150 and the double-side coated electrode sheet 161, the current collector 110 is formed to be 15% larger than the current collector 167 The cathode active material 125 can not directly contact the needle-shaped conductor 700, thereby preventing overheating or explosion due to an internal short circuit.

3 is a schematic perspective view of an electrode assembly 130 and a pouch case 220 according to an embodiment of the present invention. FIG. 4 illustrates an electrode assembly 130 according to an embodiment of the present invention. Shaped battery cell 200 in which a battery pack 200 is embedded.

3 and 4, the pouch type battery cell 200 includes electrode tabs 132 and 134 extending from the electrode assembly 130 and electrode leads (not shown) welded to the electrode tabs 132 and 134 140, and 141, and a pouch-type case 220 that accommodates the electrode assembly 130.

The pouch-shaped case 220 is made of an aluminum laminate sheet, and provides a space 223 for accommodating the electrode assembly 130, and has a pouch shape as a whole.

The pouch-shaped battery cell 200 is completed when the outer surface of the pouch-shaped case 220 has the electrode assembly 130 built therein, and the outer surface of the pouch-

5 is a perspective view schematically showing the internal structure of a pouch-shaped battery cell 200 of FIG. 4 and a secondary battery cell 500 including configurations for a smart card function.

5, the electrode terminals 140 and 141 of the pouch-shaped battery cell 200 and the protection circuit module (PCM) 400 are electrically connected to each other in a card-shaped battery case 520, The protection circuit module 400 is electrically connected to the external input / output terminal 420.

In addition, the secondary battery cell 500 includes an RFID chip 530 having a radio-frequency identification function.

The card-shaped battery case 520 is a thin film, and is further coated on the outer surface of the pouch-shaped case 220.

6 is a schematic plan view of a card-shaped secondary battery cell 500 according to an embodiment of the present invention.

6, the secondary battery cell 500 includes a pouch type battery cell 200 and a universal serial bus USB port (not shown) electrically connected to the protection circuit module 400 600 are formed on one side of the top of the battery case 520. However, the present invention is not limited to the position of the USB port 600 of FIG. 6, and the position of the USB port 600 may be formed at the upper center or one side of the secondary battery cell 500.

In the secondary battery cell 500, a barcode label 540 is attached to an outer surface of the battery case 520, and an IC chip 510 for performing a function of a smart card is located.

FIG. 7 is a schematic diagram for supplying power to an external device using the card-shaped secondary battery cell 500 of FIG.

7, when the USB port 600 of the card-shaped secondary battery cell 500 according to the present invention is connected to a USB terminal located below the mobile device 800, the mobile device 800 is charged or operated And power is supplied to the portable camera 900 so that the portable camera 900 can be similarly charged or operated.

Therefore, the card-shaped secondary battery cell 500 according to the present invention can be easily mounted on an external electronic device including a USB terminal.

It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (15)

A stacked electrode assembly in which a plurality of sheet-like electrodes and separators are alternately stacked is mounted in a sealed state in a card-shaped battery case, and at least one of the uppermost electrode and the lowermost electrode of the electrode assembly faces the separation membrane Wherein an electrode active material is coated on one surface and an electrode active material is not coated on the other surface. The secondary battery cell according to claim 1, wherein the uppermost electrode and the lowermost electrode of the electrode assembly each have an electrode active material coated on one side facing the separation membrane and no electrode active material on the other side. The electrode assembly according to claim 1,
A first electrode composed of at least one double-coated electrode sheet (1a) coated with a first electrode active material on both surfaces and at least two single-coated electrode sheets (1b) coated with a first electrode active material on one surface;
A second electrode composed of two or more double-coated electrode sheets 2a on both sides of which a second electrode active material is applied; And
Four or more separation membranes interposed between the electrode sheets;
And the second battery cell. The secondary battery cell according to claim 3, wherein the two or more single-sided coated electrode sheets (1b) are located at both outermost ends of the electrode assembly so that the uncoated side faces the outer surface of the electrode assembly. The secondary battery cell according to claim 3, wherein the first electrode is an anode and the second electrode is a cathode. The secondary battery cell according to claim 3, wherein the collector of the first electrode is 5 to 30% thicker than the collector of the second electrode. 4. The secondary battery according to claim 3, wherein the collector of the one-side coated electrode sheet (1b) is 5 to 30% thicker than the collector of the double-coated electrode sheet (2a) Cell. The secondary battery cell according to claim 1, wherein the electrode assembly includes a gel polymer electrolyte. The secondary battery cell according to claim 1, wherein the electrode assembly is sealed in a pouch-shaped case of a laminate sheet including a metal can or a metal layer and a resin layer. 10. The secondary battery cell according to claim 9, wherein the pouch-type case is sealed by thermally fusing or adhering the outer circumferential surface with the electrode assembly incorporated therein. The secondary battery cell according to claim 1, wherein a protection circuit module (PCM) is electrically connected to an electrode terminal of the secondary battery cell. 12. The secondary battery cell according to claim 11, wherein a USB port of a universal serial bus standard is connected to an external input / output terminal of the PCM. The secondary battery cell according to claim 1, further comprising an RFID chip and an integrated circuit (IC) chip having a Radio-Frequency Identification function in the battery case. The secondary battery cell according to claim 1, wherein a bar code is printed on the outer surface of the battery case or a bar code label is attached thereto. 15. The secondary battery according to claim 14, wherein the bar code label comprises a base film made of a resin having transparency and printability, and the base film is made of polyester (PE) or polyethylene terephthalate (PET) Cell.

Images